Recent Submissions

  • Accuracy of loop-mediated isothermal amplification for the diagnosis of Clostridium difficile infection: a systematic review

    Lloyd, Aaron; Pasupuleti, Vinay; Thota, Priyaleela; Pant, Chaitanya; Rolston, David D.K; Hernández, Adrian V.; Benites Zapata, Vicente A.; Fraser, Thomas G.; Donskey, Curtis J.; Deshpande, Abhishek (Elsevier B.V., 2015-02-24)
    Loop-mediated isothermal DNA amplification (LAMP) are currently used as standalone diagnostic test for C. difficile infection (CDI). We assessed the diagnostic accuracy of LAMP for the diagnosis of CDI. We searched 5 databases to identify studies that compared LAMP with culture cytotoxicity neutralization assay or anaerobic toxigenic culture (TC) of C. difficile. We used the random-effects model to calculate pooled sensitivities, specificities, diagnostic odds ratios and their 95% confidence intervals (CIs). The search of the databases yielded 16 studies (6,979 samples) that met inclusion criteria. When TC was used as the gold standard (6,572 samples), bivariate analysis yielded a mean sensitivity of 0.95 (95%CI, 0.93-0.97; I2 = 67.4) and a mean specificity of 0.99 (95%CI, 0.96-1.00; I2 = 97.0). LAMP is a useful diagnostic tool with high sensitivity and specificity for detecting CDI. The results should however be interpreted only in the presence of clinical suspicion and symptoms of CDI.
  • Impaired Functional Capacity Predicts Mortality in Patients with Obstructive Sleep Apnea

    Nisar, Shiraz A.; Muppidi, Raghunandan; Duggal, Sumit; Hernández, Adrian V.; Kalahasti, Vidyasagar; Jaber, Wael; Minai, Omar A. (The American Thoracic Society, 2014-12-16)
    Background: Obstructive sleep apnea (OSA) is associated with increased mortality, for which impaired functional capacity (IFC) has been established as a surrogate. We sought to assess whether IFC is associated with increased mortality in patients with OSA and whether IFC is predictive of increased mortality after accounting for coronary artery disease. Methods: Patients with OSA who underwent both polysomnography testing and exercise stress echocardiogram were selected. Records were reviewed retrospectively for demographics, comorbidities, stress echocardiographic parameters, and polysomnography data. Univariable and multivariable logistic regression analysis was used to evaluate the association between IFC and overall mortality. We then evaluated the variables associated with IFC in the overall population and in the subgroup with normal Duke treadmill score (DTS). Results: In our cohort, 404 (26%) patients had IFC. The best predictors of IFC were female sex, history of smoking, ejection fraction less than 55, increased body mass index, presence of comorbidities, abnormal exercise echocardiogram, abnormal heart rate recovery, and abnormal DTS. Compared with those without IFC, patients with IFC were 5.1 times more likely to die (odds ratio [OR], 5.1; 95% confidence interval [CI], 2.5–10.5; P , 0.0001) by univariate analysis and 2.7 times more likely to die (OR, 2.7; 95% CI, 1.2–6.1; P = 0.02) by multivariate analysis, when accounting for heart rate recovery, DTS, and sleep apnea severity. Among those without coronary artery disease, patients with IFC were at significantly increased risk of mortality (OR, 4.3; 95% CI, 1.35–13.79; P = 0.0088) compared with those with preserved functional capacity. Conclusions: In our OSA population, IFC was a strong predictor of increased mortality. Among those with normal DTS, IFC identified a cohort at increased risk of mortality.
  • Factors predicting incremental administration of antihypertensive boluses during deep brain stimulator placement for Parkinson’s disease

    Rajan, Shobana; Deogaonkar, Milind; Kaw, Roop; Nada, Eman MS; Hernández, Adrian V.; Ebrahim, Zeyd; Avitsian, Rafi (Elsevier B.V., 2014-11-28)
    Hypertension is common in deep brain stimulator (DBS) placement predisposing to intracranial hemorrhage. This retrospective review evaluates factors predicting incremental antihypertensive use intraoperatively. Medical records of Parkinson’s disease (PD) patients undergoing DBS procedure between 2008–2011 were reviewed after Institutional Review Board approval. Anesthesia medication, preoperative levodopa dose, age, preoperative use of antihypertensive medications, diabetes mellitus, anxiety, motor part of the Unified Parkinson’s Disease Rating Scale score and PD duration were collected. Univariate and multivariate analysis was done between each patient characteristic and the number of antihypertensive boluses. From the 136 patients included 60 were hypertensive, of whom 32 were on angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB), told to hold on the morning of surgery. Antihypertensive medications were given to 130 patients intraoperatively. Age (relative risk [RR] 1.01; 95% confidence interval [CI] 1.00–1.02; p = 0.005), high Joint National Committee (JNC) class (p < 0.0001), diabetes mellitus (RR 1.4; 95%CI 1.2–17; p < 0.0001) and duration of PD >10 years (RR 1.2; 95%CI 1.1–1.3; p = 0.001) were independent predictors for antihypertensive use. No difference was noted in the mean dose of levodopa (p = 0.1) and levodopa equivalent dose (p = 0.4) between the low (I/II) and high severity (III/IV) JNC groups. Addition of dexmedetomidine to propofol did not influence antihypertensive boluses required (p = 0.38). Intraoperative hypertension during DBS surgery is associated with higher age group, hypertensive, diabetic patients and longer duration of PD. Withholding ACEI or ARB is an independent predictor of hypertension requiring more aggressive therapy. Levodopa withdrawal and choice of anesthetic agent is not associated with higher intraoperative antihypertensive medications.
  • Animales..¿En peligro de extinción o en peligro de que los extingamos?

    Rodríguez García, Gustavo; grodriguez.gustavo@gmail.com (Facultad de Ciencias Jurídicas y Sociales, Universidad de Talca, 2014-08-12)
    This paper presents the issue of endangered species from a Law & Economic's perspective. In this way, instead of defending the creation of legal mechanisms oriented to public protection of animals (seen as a heritage of humanity), the author maintains the reasons why animals should be considered under a private property regime that provides incentives for their care and for productivity.
  • Association between obesity and postoperative atrial fibrillation in patients undergoing cardiac operations: a systematic review and meta-analysis

    Hernández, Adrian V.; Kaw, Roop; Pasupuleti, Vinay; Bina, Pouya; P. A. Ioannidis, John; Bueno, Hector; Boersma, Eric; Gillinov, Marc (Elsevier B.V., 2014-07-03)
    In a systematic review and random effects meta-analysis, we evaluated whether obesity is associated with postoperative atrial fibrillation (POAF) in patients undergoing cardiac surgery. Eighteen observational studies that excluded patients with preoperative AF were selected until December 2011 (n=36,147). Obese patients had a modest higher risk of POAF in comparison to non-obese (OR 1.12, 95%CI 1.04-1.21, p=0.002). The association between obesity and POAF did not vary substantially by type of cardiac surgery, study design or year of publication. POAF was significantly associated with higher risk of stroke, respiratory failure, and operative mortality.
  • Inferior vena cava filters and postoperative outcomes in patients undergoing bariatric surgery: a meta-analysis

    Kaw, Roop; Pasupuleti, Vinay; Overby, D.Wayne; Deshpande, Abhishek; Craig I. Coleman Pharm; John P.A. Ioannidis; Hernández, Adrian V. (Elsevier B.V., 2014-06-09)
    Background: Pulmonary embolism (PE) accounts for almost 40% of perioperative deaths after bariatric surgery. Placement of prophylactic inferior vena cava (IVC) filter before bariatric surgery to improve outcomes has shown varied results. We performed a meta-analysis to evaluate postoperative outcomes associated with the preoperative placement of IVC filters in these patients. Methods: A systematic review was conducted by three investigators independently in PubMed, EMBASE, the Web of Science and Scopus until February 28, 2013. Our search was restricted to studies in adult patients undergoing bariatric surgery with and without IVC filters. Primary outcomes were postoperative deep vein thrombosis (DVT), pulmonary embolism (PE), and postoperative mortality. Meta-analysis used random effects models to account for heterogeneity, and Sidik-Jonkman method to account for scarcity of outcomes and studies. Associations are shown as Relative Risks (RR) and 95% Confidence Intervals (CI). Results: Seven observational studies were identified (n=102,767), with weighted average incidences of DVT (0.9%), PE (1.6%), and mortality (1.0%) for a follow-up ranging from 3 weeks to 3 months. Use of IVC filters was associated with an approximately 3-fold higher risk of DVT and death that was nominally significant for the former outcome, but not the latter (RR 2.81, 95%CI 1.33-5.97, p=0.007; and RR 3.27, 95% CI 0.78-13.64, p=0.1, respectively); there was no difference in the risk of PE (RR 1.02, 95%CI 0.31-3.77, p=0.9). Moderate to high heterogeneity of effects was noted across studies. Conclusions: Placement of IVC filter before bariatric surgery is associated with higher risk of postoperative DVT and mortality. A similar risk of PE in patients with and without IVC filter placement cannot exclude a benefit, given the potential large imbalance in risk at baseline. Randomized trials are needed before IVC placement can be recommended.
  • Association between Insulin Resistance and Breast Carcinoma: A Systematic Review and Meta-Analysis

    Hernández, Adrian V.; Guarnizo, Mirella; Miranda, Yony; Pasupuleti, Vinay; Deshpande, Abhishek; Paico, Socorro; Lenti, Hosten; Ganoza, Silvia; Montalvo, Laritza; Thota, Priyaleela; Lazaro, Herbert (Public Library of Science (PLoS), 2014-06-09)
    Objective: This study was undertaken to evaluate the association between components defining insulin resistance and breast cancer in women. Study Design: We conducted a systematic review of four databases (PubMed-Medline, EMBASE, Web of Science, and Scopus) for observational studies evaluating components defining insulin resistance in women with and without breast cancer. A meta-analysis of the association between insulin resistance components and breast cancer was performed using random effects models. Results: Twenty-two studies (n = 33,405) were selected. Fasting insulin levels were not different between women with and without breast cancer (standardized mean difference, SMD 20.03, 95%CI 20.32 to 0.27; p = 0.9). Similarly, non-fasting/ fasting C-peptide levels were not different between the two groups (mean difference, MD 0.07, 20.21 to 0.34; p = 0.6). Using individual odds ratios (ORs) adjusted at least for age, there was no higher risk of breast cancer when upper quartiles were compared with the lowest quartile (Q1) of fasting insulin levels (OR Q2 vs. Q1 0.96, 0.71 to 1.28; OR Q3 vs. Q1 1.22, 0.91 to 1.64; OR Q4 vs. Q1 0.98, 0.70 to 1.38). Likewise, there were no differences for quartiles of non-fasting/fasting C-peptide levels (OR Q2 vs. Q1 1.12, 0.91 to 1.37; OR Q3 vs. Q1 1.20, 0.91 to 1.59; OR Q4 vs. Q1 1.40, 1.03 to 1.92). Homeostatic model assessment (HOMAIR) levels in breast cancer patients were significantly higher than in people without breast cancer (MD 0.22, 0.13 to 0.31, p, 0.00001). Conclusions: Higher levels of fasting insulin or non-fasting/fasting C-peptide are not associated with breast cancer in women. HOMA-IR levels are slightly higher in women with breast cancer.
  • Efficacy of 5-Nitroimidazoles for the Treatment of Giardiasis: A Systematic Review of Randomized Controlled Trials

    Pasupuleti, Vinay; Escobedo, Angel Arturo; Deshpande, Abhishek; Thota, Priyaleela; Roman, Yuani; Hernández, Adrian V. (Public Library of Science (PLoS), 2014-05-03)
    Background: Giardiasis is one of the most common causes of diarrheal disease worldwide and 5-nitroimidazoles (5-NI) are the most commonly prescribed drugs for the treatment of giardiasis. We evaluated the efficacy of 5-nitroimidazoles (5-NI) in the treatment of giardiasis in a systematic review of randomized controlled trials (RCTs). Methodology/Principal Findings: We conducted a comprehensive literature search in PubMed-Medline, Scopus, Web of Science and Cochrane Library for RCTs evaluating the efficacy of 5-NI vs. control (placebo or active treatment) on parasitological cure in patients with parasitologically-demonstrated giardiasis. The search was performed in May 2013 with no language restriction by two authors independently. The efficacy outcome was parasitological cure, and harmful outcomes were abdominal pain, bitter or metallic taste, and headache. We included 30 RCTs (n = 3,930). There was a significant and slightly higher response rate with 5-NI in giardiasis treatment (RR 1.06, 95%CI 1.02–1.11, p = 0.005). There was high heterogeneity among studies (I2= 72%). The response rates for metronidazole, tinidazole and secnidazole were similar (RR 1.05, 95%CI 1.01–1.09, p = 0.01; RR 1.32 95%CI 1.10–1.59, p = 0.003; and RR 1.18 95%CI 0.93–1.449, p = 0.18, respectively). On subgroup analyses, the response rates did not vary substantially and high heterogeneity persisted (I2= 57%–80%). Harmful outcomes were uncommon, and 5-NIs were associated with lower risk of abdominal pain, and higher risk of both bitter or metallic taste and headache. Conclusions: Studies investigating the efficacy of 5-NI in giardiasis treatment are highly heterogeneous. 5-NIs have a slightly better efficacy and worse profile for mild harmful outcomes in the treatment of giardiasis in comparison to controls. Larger high quality RCTs are needed to further assess efficacy and safety profiles of 5-NI.